I certainly agree that C is most appropriate when you are "low in the stack," just above the operating system and maybe implementing something like a virtual machine. I don't make a habit of writing stuff in C for no reason and the vast majority of programming these days isn't and shouldn't be in C (or C++ for that matter).
However, "low in the stack" is different from "low level" like "I refuse to use modern practices" or "I get to omit half the letters from my function names." You can be coding an on-the-metal kind of thing and still think about it in a high level way.
1. Building static libraries. 2. Building so and dll. 3. Binding those so/dll with higher level languages like Ruby, Python, Perl and PHP.
That is my main use of C these days. I always write the IO, user interface code in higher level languages and put all processing code in a so or dll written in C.